There is a growing trend to incorporate computer-like functions into television or television-based devices. Internet use is area where this is happening. Internet browsing devices are now available for use with televisions. When using devices such as these, visual and audio Internet content are rendered by the television equipment rather than by dedicated computer peripherals.
In the desktop computer environment, substantial attention has been given to selecting appropriate methods of user interaction. At the moment, the Windows family of operating systems, available from Microsoft Corporation, utilizes what seems to be the most popular user interface.
The Windows operating systems emphasize the use of a mouse in conjunction with an on-screen pointer and a plurality of on-screen objects or controls. The mouse can be moved across a flat surface in different directions to produce a corresponding analog movement of the on-screen pointer. This method of moving a pointer is referred to as "roaming."
Objects or controls, also referred to as icons, represent functions or items that are available for a user to select. To select an object, the user moves the pointer over the object and depresses or "clicks" a button on the mouse. The operating system responds by performing an appropriate action, depending on the nature of the selected object.
Although this type of user interface works well in the desktop environment, it is not nearly as effective when transferred to the television environment. In the television environment, the user is typically sitting on a couch or recliner at some distance from the image displayed by the television. As a further complication, most televisions have much lower display resolutions than typical computer monitors. These factors make it somewhat more difficult to display and position objects and mouse pointers. Additionally, the user's viewing situation often does not lend itself to the use of a mouse. Rather, the user is often more comfortable with an IR (infrared) control with more rudimentary controls such as a set of orthogonal direction keys. Finally, apart from physical constraints, positioning an on-screen pointer simply requires more concentration that a casual user is willing to put forth during a time intended for relaxation or recreation.
As a result of these factors, many television-related products now use a so-called "tabbing" navigation model. This model constrains the user's movement to a limited set of displayed objects. Rather than using a pointer, a "focus" is moved around the display between different objects. The focus is generally indicated by highlighting or otherwise changing the appearance of the focused object. Generally, one and only one item has the focus at any given time. To select an object, the user moves the focus from object to object using directional keys or some other type of directional control operators. As opposed to the roaming model discussed above, the focus "tabs," "jumps," or moves abruptly from one object to the next. When the focus is on the desired object, the user pushes an "action" key to select the object.
This navigational model has disadvantages. For example, modem interfaces and information content often demand the ability to select arbitrary points on a display. This is not possible with the tabbing navigational model. Furthermore, while tabbing is helpful for novice users, such users quickly become more sophisticated. To sophisticated users, tabbing is often a constraint rather than a help.
Another problem arises when information content, such as Internet content, is scrollable over a displayed area. In this situation, it is desirable for the directional control keys to also initiate scrolling at appropriate times. This can be accomplished by automatically scrolling the content so that the next focused object is on-screen. However, this often results in an annoying lack of continuity and in unintended focus movement, especially when focusable objects are far from each other in the information content. For this reason, most popular user interfaces utilize two different methods or input sequences for focus movement and scrolling, respectively.